microinvertebrates

Microinvertebrates are small invertebrate animals, typically measuring less than 1 millimeter in size. The term is informal and not tied to a single taxonomic group, encompassing a broad array of phyla whose individuals are tiny or require magnification to be seen clearly. They inhabit a wide range of environments, especially aquatic systems and moist soils, leaf litter, and sediments.

Representative groups include nematodes (roundworms), rotifers, gastrotrichs, tardigrades, and various microcrustaceans such as ostracods, copepods, and cladocerans. Many microinvertebrates act as consumers of bacteria and algae, detritivores that break down organic matter, or prey for larger animals. They contribute to nutrient cycling, soil structure, and energy flow in ecosystems. Some species are sensitive to environmental conditions and are used as bioindicators of pollution or habitat degradation.

Studying microinvertebrates involves collecting samples from water, soil, or sediment, separating organisms by size through sieving and flotation, and identifying them under a microscope. Molecular methods, including DNA barcoding, are increasingly used for precise identification. Preservation often uses ethanol or formalin, while live observation may require specialized chambers. As a component of microfauna and meiofauna, they are central to ecological research and environmental monitoring.